Isometric 30° · 5 mm
The textbook isometric grid - three axes at 120°, 5 mm cell pitch.
Isometric grids project all three principal axes at 30° from horizontal, equally spaced 120° apart. Equal foreshortening on every face is what makes isometric measurable - a 5 mm cell on the page represents 5 mm on every face of the modelled solid. Background: A reading list on technical-drawing standards.
The textbook isometric grid - three axes at 120°, 5 mm cell pitch.
The bold 10 mm centimetre-pitch isometric - open, presentation-ready.
Generous 20 mm isometric - for whole-building axonometric drawings.
Dense isometric for jewellery, electronics and millimetre assemblies.
Equilateral triangular lattice - for tessellation and structural studies.